Silver Solder Questions

[ba-brewer]

Pictures below are two 1.5" TC I silver soldered to a economy kettle. I clean it after it cooled with acetone then multiple sessions of barkeepers friend. When I fill it up with water I get a milky substance forming on the solder and drifting up and down the side of the kettle. Pictures below are taken with water in the kettle. I can wipe the stuff off and it returns in an hour or two. I used Harris Stay Brite #8 and liquid stay clean flux.

Guessing it some sort of oxidation but the fact that there is visible stuffing coming into the water makes me nervous.

Q: Does this look right?
Q: OK to use?
Q: I missed the part to wipe off excess solder with a damp rag, will reheating then wiping off the excess fix the problem?

 

[day_trippr]

Gotta be Stay Brite flux deposits dissolving, right?
I mean, the solder metal itself isn't going anywhere, and the flux is supposed to be water soluble.

The quick wipe of the joint with a dry rag is a copper plumbing finesse move. I'm a fan.
Not sure it's worth risking a void to reheat that fitting, though...

Cheers!

 

[ba-brewer]

It seemed like the solder was milky/whitish all over but looking closer maybe it just in the knocks and crannies and it could be the flux.

After a few cleaning and soak cycles I have been just allowing it to soak and it sort of seems one side may be showing less but still enough to see it. I did a boil test maybe doing that again would help speed up the process if it is flux dissolving.

I took a brush to it, maybe do it again when it is submerged in warmer water.

 

[Ruint]

Have you tried a stiff mix of pbw and letting that soak for a bit ba-brewer? Thinking that might help speed the dissolving. Vinegar or maybe a citric acid solution.... Not sure if those would have a super impact on those metals....maybe someone could chime in with that, but should definitely help get rid of any residues left from the flux. Haven't done silver solder before but have soldered a LOT of copper piping together and normal flushing with water was all that was ever needed.

 

[ba-brewer]

Thanks for the ideas @Ruint.

I did a couple hour warm water soak of PBW, rinsed then refilled the kettle but still happened. Did an overnight soak followed by a rinse and another refill, still happened.

Did a three hour boil, cleaned the kettle and refilled, still happened.

Reheated to melted the solder and wiped off excess solder/flux when hot. Same thing. I did clean with BKF first and it seemed like it was worst initially after cleaning.

I then filled with RO water. No milky stuff. I let it sit for almost 24hrs and nothing. Refilled with tap water and within 30min the milky stuff appeared.

I was thinking it was flux trapped in the joint or in encrusted solder but now think it is some sort of reaction to something in my tap water.

I did find a jewelry making web site that implied a white residue on a silver solder was residual flux.
https://ourpastimes.com/how-to-clean-flux-residue-after-soldering-12268563.html

Going to put a piece of solder in a glass of water and see what happens.

 

[Ruint]

Guess you are just not going to be able to brew with simple tap water! Is that city water or from a well? That is awesome detective work btw!!! Unfortunate as it may be, it's good to at least have a lead to go on.

 

[ba-brewer]

It is unfiltered city water. I do drink the water and it tastes fine, it is not too minerally and does have chloramine. The water source can change seasonally but most of it is surface water from the Sacramento river delta.

I make RO water and build it up for brewing. Suppose I should see if my normal salt additions do the same thing.

Don't think you would be able tell if it happens with wort.

 

[Ruint]

I am thinking it is more due to the chloramine. It'd be interesting to see if any of the additions to your water recipe effectively trigger that cloudy reaction. Do you know the chemistry make up of your tap water. Might want to see about getting it, just for comparison purposes. Your RO shouldn't have anything in it, your tap water does, therefore when building up your water, you might get a reaction, and by comparing, you might be able to match up similar levels of any given additions.....if you don't get any reactions, then obviously it would be something that has not been put into the recipe that is present in the tap....at least that's what I would think...lol

 

[ba-brewer]

They publish an annual report, I can take a look. I know this does not mean much but my RO takes the TDS from about 220 to 5-10ppm.

Got it back on RO to double check the first observation then was planning to add salts all at once, but maybe adding in stages might show if one type can trigger an reaction.

If it is the chloramine I could see if Camden added to the tap water fixes the problem.

I am glad I have other kettles to brew with and this was sort of an experiment to checkout the silver solder process.

 

[Ruint]

Looks like you had a plan even before I added my two cents!! Very good! Now just gonna hang out to see what the culprit is.

 

[ba-brewer]

Latest finds;
A chunk of silver solder in a glass of my tap water stays shiny has no residue after a 24hr soak. Same chunk cleaned with barkeepers friend, turned a dull color before the soak but still did not produce any residue after a 48 soak.

Added .1gm of Camden to 3gal of tap water then added to the kettle, still produces a milky residue.

Added .6gm of kosher salt to 3gal RO and was able to produce some residue but it stopped after about 24hrs. That seemed to leave a dark ring around the kettle after a couple days. Bar keepers friend cleaned it off with a couple scrubbings.

Going to take a break for awhile, but next test will be to try different single mineral addition to RO to try match my local tap water.

snip of my local water report, I get the treated surface water in my part of town.

 

[deanomite]

@ba-brewer I am facing the same issue. Did you ever resolve this?

 

[ba-brewer]

@deanomite I gave up and went with a bulkhead type solution.

I believe I tried more cleaning but was never able to get rid of the issue. I still have the kettle but don't use it.